1. Field of the Invention
The present invention generally relates to cylindrical mounting apparatuses equipped with brackets, which are useful as mounts for automotive vehicles, such as engine mounts, body mounts, deferential mounts and cab mounts. More specifically, the invention is concerned with a cylindrical mounting apparatus, which is novel in construction and which ensures improved efficiency in assembling the cylindrical mount with the bracket.
2. Description of the Related Art
A cylindrical mount is known as one type of a vibration damping coupling (bushing) or mount, which is interposed between two members of a vibration system so as to flexibly connect these two members or mount one of these members on the other member in a vibration damping fashion. A known cylindrical mount includes a metallic inner and outer sleeve which are disposed in mutually spaced-apart relation with each other, and an elastic body interposed between the inner and outer sleeves so as to elastically connect the inner and outer sleeves. The known cylindrical mount is capable of exhibiting desired damping effects with respect to various kinds of vibrations applied thereto in a plurality of directions orthogonal to a center axis thereof.Byforming axial bores in the elastic body, the cylindrical mount can be easily tuned in terms of a ratio of spring stiffness values in different diametric directions thereof. For the above advantages, the cylindrical mount has been widely used as engine mounts, body mounts or other mounts for automotive vehicles.
When installing such a cylindrical mount into a desired vibration system, it is important to fixedly attach the inner and outer sleeves to respective members of the vibration system, e.g., a power unit and a body of an automotive vehicle. To this end, there has been widely employed to use a bracket specifically configured in consideration of configurations or other features of seat portions of the respective members of the vibration system so that the inner and outer sleeves are firmly attached on the seat portions of the respective members of the vibration system via the bracket. In this regards, a bracket for the inner sleeve generally includes a pair of support plates opposed to each other with a spacing substantially corresponding to an axial length of the inner sleeve. The cylindrical mount is inserted into the spacing between the pair of support plates of the bracket and fixed firmly to the bracket by fastening a long mounting bolt extending through a bore of the inner sleeve and through holes formed through the respective support plates to the bracket.
However, the bracket of conventional structure as described above requires manual operations in a blind manner: of inserting the cylindrical mount into the spacing between the support plates; of arranging the bore of the inner sleeve in alignment with the through holes of the support plates; and of inserting the bolt into these through holes of the support plates and the bore of the inner sleeve to fasten the same to the bracket. Therefore, the use of the bracket of conventional structure inevitably requires cumbersome and prolonged operations, and causes a problem of variation in operation efficiency depending on skills of operators.
Additionally, many conventional cylindrical mounts require adjustment of their angular orientations when assembled with the brackets, in consideration of their spring characteristics in diametric directions orthogonal to their axial directions. In each case, the conventional cylindrical mount needs further a manual operation for appropriately positioning the cylindrical mount about its center axis, in addition to the above-described cumbersome manual operations. This makes the assembly more complicate, and may possibly cause deterioration in operability as well as occurrence of defective products due to directional errors during assembling the cylindrical mounts with the bracket.
JP-A-2001-180296 discloses one example of the conventional cylindrical mount wherein a bracket of sideway U-letter shape has opposite side walls between which the cylindrical mount is extended. A pair of reinforcing plates are welded to respective inside surfaces of the opposite side walls of the bracket, to thereby provide stoppers projecting inwards from the respective inside surfaces of the opposite side walls in order to mark the ending of insertion of the cylindrical mount into the bracket. However, the stoppers just make it possible to position the cylindrical mount relative to the bracket in a direction of insertion of the cylindrical mount to the bracket, it is still difficult to position the inner sleeve of the cylindrical member in alignment with bolt holes formed through the bracket. In particular, the angular orientation of the cylindrical mount is not taken into consideration at all in the cylindrical mount of construction disclosed in JP-A-2001-180296. If it is needed to consider the angular orientation of a cylindrical mount when assembling the cylindrical mount with the bracket, the structure or other teaching of the cylindrical mount disclosed in JP-A-2001-180296 never shows a measure for this problem, i.e. for appropriately positioning the cylindrical mount in its circumferential direction.
It is therefore one object of this invention to provide a cylindrical mounting apparatus equipped with a bracket, which is novel and simple in construction, which makes it easy to insert a mounting bolt into a bore of an inner sleeve of a cylindrical mount to fasten the mount into the bracket, and which makes it possible to assemble the cylindrical mount with the bracket with ease and excellent efficiency.
The above and/or other objects may be attained according to at least one of the following modes of the invention. Each of these modes of the invention is numbered like the appended claims and depending from the other mode or modes, where appropriate, to indicate possible combinations of elements or technical features of the invention. It is to be understood that the following modes or elements of the invention may be adopted at any possible optional combinations, and that the present invention is not limited to the following modes or combinations of these modes, but may otherwise be recognized based on the thought of the present invention that described in the whole specification and drawings or that may be recognized by those skilled in the art in the light of the disclosure in the whole specification and drawings.
(1) A cylindrical mounting apparatus equipped with a bracket comprising: (a) a cylindrical mount including an inner and outer sleeve disposed in mutually spaced-apart relation with each other, and an elastic body interposed between the inner and outer sleeves so as to elastically connect the inner and outer sleeves; (b) a bracket independent of the cylindrical mount, having a pair of support plates opposed to each other with a spacing therebetween, and assembled with the cylindrical mount such that the cylindrical mount is inserted into the spacing between the pair of support plates and fasten to the bracket by means of a mounting bolt extending through a bore of the inner sleeve across the pair of support plates; (c) two positioning protrusions formed on and protruding from at least one of the pair of support plates toward an other of the pair of support plate; and (d) a mounting plate disposed on one of axially opposite end portions of the inner sleeve so as to extend in a direction orthogonal to an axial direction of the inner sleeve, the mounting plate being held in contact with an inside surface of the at least one of the pair of support plates, and having an engaging portion of recessed shape, which is open in an outer circumferential surface of the mounting plate, and which is brought into abutting contact with the two positioning projections so as to place the mounting plate in a predetermined position about a center axis of the inner sleeve on the inside surface of the at least one of the pair of support plates.
The cylindrical mounting apparatus constructed according to this mode of the invention is capable of positioning the cylindrical mount and the bracket relative to each other through a simple positioning structure effectively utilizing an engagement between the mounting plate formed on the inner sleeve of the cylindrical mount and at least two positioning protrusions formed on the support plate. Described in detail, by superposing the mounting plate of the cylindrical mount onto the support plate of the bracket, the inner sleeve of the cylindrical mount can be positioned relative to the bracket in its axial and diagonal (torsional) directions. With the inner sleeve of the cylindrical mount positioned relative to the bracket in its axial and diagonal directions as described above, the recess-shaped engaging portion of the mounting plate is brought into engagement with the two positioning protrusions formed on the support plate of the bracket, thereby positioning the inner sleeve of the cylindrical mount relative to the bracket in a circumferential direction about the center axis of the inner sleeve and in one diametric direction of the inner sleeve. Thus, the inner sleeve of the cylindrical mount can be easily and efficiently positioned in the predetermined position on the support plate of the bracket, where a bore of the inner sleeve is in alignment with the through holes formed through the pair of support plates.
The adoption of the above-described simple positioning structure permits an easy and quick positioning of the cylindrical mount and the bracket when assembling the mount and the bracket. Additionally, the bore of the inner sleeve is in alignment with the through holes of the support plates when the inner sleeve of the cylindrical mount is placed in the desired position relative to the bracket, making it easy to quickly insert the mounting bolt into the through holes of the support plates and the bore of the inner sleeve. According to the present mode of the invention, the cylindrical mount can be easily, efficiently and stably assembled with the bracket, without needing sophisticated skills of operators, thereby skyrocketing efficiency in assembling operation.
According to this mode of the invention, the cylindrical mount may have a variety of configurations without any specific limitation. For instance, it is certainly possible as a matter of design to form slits or bores of suitable shape and size into the elastic body elastically connecting the inner and outer sleeves, for suitably adjusting the spring characteristics of the cylindrical mount. It is also possible to adopt a variety of conventional fluid filled cylindrical mounts each having a fluid chamber partially defined by the elastic body and filled with a non-compressible fluid so as to exhibit vibration damping effect with the help of resonance or flows of the non-compressible fluid. Similarly, the bracket may be suitably designed with no limitation in terms of its shape, size or the like, depending on a shape or structure of a member of a vibration system, such as an engine mount, to which the bracket is attached. Also, the bracket is not limited in terms of its material, structure or the like. For instance, aluminum alloy products formed by protruding and products formed of welded steel plates may be adoptable as a bracket with no limitation. Further, the mounting plate may be integrally formed on the inner sleeve of the cylindrical mount, or alternatively bonded to the inner sleeve by welding, pressing, fixing or the like. Also, the mounting plate may have a variety of configurations including a disk shape, an ellipsoidal disk shape and a polygonal plate shape.
The configuration of the engaging part is not particularly limited provided that the engaging part of the mounting plate is formed with a cutout or recessed shape in order to ensure that the engaging part is brought into engagement with the positioning protrusions formed on the support plate of the bracket so that the inner sleeve of the cylindrical mount is positioned relative to the bracket in its diametric and circumferential directions. For instance, the engaging part may be divided into mutually independent two engaging sections brought into engagement with the positioning protrusions, respectively, or alternatively has a cutout shape in which two engaging sections adapted to be engaged with the respective positioning protrusions are circumferentially contiguous to each other, which will be described as a second mode.
(2) A cylindrical mounting apparatus according to the above indicated mode (1), wherein the engaging portion comprises a cutout portion formed at a peripheral portion of the mounting plate, extending circumferentially with a circumferential length not larger than a half of a circumference of the mounting plate, and circumferentially opposite end portions of the cutout portion are brought into engagement with the two positioning protrusions of the at least one of the pair of support plates, respectively.
According to this mode of the invention, the engaging part of the mounting plate is made large in the circumferential direction. This permits that one of the two positioning protrusions is first inserted into the cutout portion, and then the other positioning protrusion is inserted into the cutout portion by rotating the mounting plate and the other positioning protrusion relative to each other in the circumferential direction, making it more easy to bring the engaging portion of the mounting plate into an engagement with the positioning protrusions. Preferably, the cutout portion is shaped to expand gradually in its circumferential dimension toward the peripheral portion of the mounting plate. This further facilitates more operation for bringing the cutout portion into the two positioning protrusions.
(3) A cylindrical mounting apparatus equipped with a bracket according to the above indicated mode (2), further comprising a plate-form member independent of the cylindrical mount and the bracket, the plate-form member being superposed on the mounting plate, sandwiched between and supported by the mounting plate and the at least one of the pair of support plates, and having an engaging jaw brought into engagement with a circumferentially intermediate portion of the cutout portion of the mounting plate. While, in general, cylindrical mounts may be optionally provided with plate-form members, e.g., heat insulating plates (insulators) or stopper plates for engine mounts and guide or support plates for assembly, the arrangement according to this mode of the invention makes it possible to easily and quickly attach such a plate-form member to the cylindrical mounting device at the same time when the cylindrical mount assembled with the bracket, by compressing the plate-form member by and between the mounting plate of the cylindrical mount and the support plate of the bracket. A further advantage of this mode is that the engaging jaw formed at the plate-form member is arranged to be held in contact with the circumferentially intermediate portion of the cutout portion, which portion is remote from other circumferential portions of the cutout portion that are adapted to be held in engagement with the positioning protrusions, thereby eliminating a need for an additional arrangement applied to the mounting plate for receiving the engaging jaw.
(4) A cylindrical mounting apparatus equipped with a bracket according to the above-indicated mode (3), wherein the mounting plate has a disk-like shape and includes two of the cutout portions located at respective portions diametrically opposed to each other, and wherein one of the cutout portions is adapted to be brought into engagement with the engaging jaw at the circumferentially intermediate portion thereof, and the plate-form member includes an engaging projection adapted to be brought into engagement with circumferentially opposite end portions of an other of the cutout portions so that the plate-form member is placed in a predetermined position on the mounting plate as a result of engagement of the two cutout portions with the engaging jaw and the engaging projections, respectively. According to this mode of the invention, an axial positioning of the plate-form member can be established by compressing the plate-form member by and between the mounting plate of the cylindrical mount and the support plate of the bracket, while a diametrical and circumferential positioning of the plate-form member can also be established by means of the engagement of the engaging jaw as well as the positioning projections of the plate-form member with the respective cutout portions of the mounting plate. That is, the present mode of the invention makes it possible to quickly and easily fix the plate-form member to the cylindrical mounting apparatus, through the simple structure as described above.
(5) A cylindrical mounting apparatus equipped with a bracket according to any one of the above-indicated modes (1)-(4), wherein a specific angular orientation of the cylindrical mount is determined for assembling the cylindrical mount with the bracket. According to this mode of the invention, with the held of the engagement of the engaging part of the mounting plate with the positioning protrusions of the bracket, the cylindrical mount can be assembled with the bracket with its angular orientation desirably set. Therefore, a serious attention to the angular orientation of the cylindrical mount is no longer required for assembling the cylindrical mount with the bracket, thereby eliminating or minimizing occurrence of miss assembly
(6) A cylindrical mounting apparatus equipped with a bracket according to any one of the above-indicated modes (1)-(5), wherein the outer sleeve includes a flange-form portion formed at one of axially opposite ends thereof so as to extend in a radially outward direction of the outer sleeve, the flange-form portion being opposed to the mounting plate of the inner sleeve with an axial spacing therebetween, and elastically connected with the mounting plate by the elastic body. According to this mode of the invention, an adjusting structure for adjusting the spring stiffness of the cylindrical mount in its axial direction is effectively embodied by utilizing the mounting plate used in the above-described positioning structure for the inner sleeve.